In the United States of America, manufacturers of child resistant closures seek to provide closures that, under test protocols, meet or exceed the Consumer Products Safety Commission child resistant safety standards.
Some types of allegedly child resistant closures made from conventional thermoplastic materials can be permanently or temporarily deformed or distorted by a child's teeth. The present inventors have learned that a child may place part of such a closure in his or her mouth and engage a portion of the closure with the front top teeth and/or with the front bottom teeth. The child may also grasp, and push or pull, the portion of the closure or container projecting from the child's mouth.
If the closure has a ledge, shoulder, indentation, groove or the like at or near the periphery of the closure, the child's teeth can effectively engage such a formation and actually deform, distort, or otherwise pry a portion of the closure away from its normal locking engagement configuration. This has been found to occur even where the child does not otherwise attempt to also directly disengage a locking member which is designed to be moved to a release position by an adult user of the closure.
Thus, it would be desirable to provide an improved child resistant closure which can be more effective in defeating a child's attempt to open the closure.
Although exceptionally strong, child resistant closures can be designed, such closures may not be commercially acceptable owing to high cost, lack of aesthetic appeal, and the difficulty of opening such closures by adults. Therefore, it would be advantageous to provide an improved closure with increased child resistance features that are not too difficult or cumbersome for adult users and that do not significantly detract from the aesthetic appeal of the closure.
It would also be beneficial if such an improved closure could be provided in the form that would not require excessively complicated manufacturing operations and that would permit the use of conventional, high-speed, automatic capping machines for applying the closures to containers.
The present invention can be embodied in designs that provide one or more of the above-discussed benefits and features.